Major Lion Die-Offs Linked to Climate Change

When the rains resumed, Babesia-carrying ticks emerged en masse and proliferated in their buffalo hosts. Many of the buffalo died.

The lions feasted on the weakened, parasite-infested buffalo, but the feast left the hunters with unusually high concentrations of Babesia. The subsequent CDV outbreak proved lethal, according to the study.

"CDV is immunosuppressive—like a short, sharp bout of AIDS—thus greatly intensifying the effects of the Babesia," Packer said.

This co-infection, or synchronization of the diseases, caused the mass die offs, Packer and his colleagues concluded.

Sonia Altizer is an ecologist who studies wildlife diseases at the University of Georgia in Athens. She was not involved with this study, which she said is "at the leading edge" of the field.

"[It] lays out mechanistically how a climate anomaly could allow a combination of pathogens to have a lethal one-two punch," she said.

Conservation Implications

Study author Packer and his colleagues warn that as global climate change continues to produce more extreme weather anomalies, potentially fatal synchronized infections are likely to become more common.